1. ## roots and radicals

Solve each equation. Round your answer to two places if necessary.
26. 1875=3a^4

32. 10.56=12.4(1-r)^20

i don't understand this two problems. the two problems are color colded.
i hope it is ok to post this two problems in this thread. if not, sorry.

2. Originally Posted by comet2000
Solve each equation. Round your answer to two places if necessary.
26. 1875=3a^4

32. 10.56=12.4(1-r)^20

i don't understand this two problems. the two problems are color colded.
i hope it is ok to post this two problems in this thread. if not, sorry.
1.
$1875 = 3a^4$
Divide both sides by 3:
$625 = a^4$
Do forth root on both sides:
$\sqrt[4] {625} = \sqrt[4] {a^4}$
$5 = a$

2.
$10.56 = 12.4(1-r)^{20}$
Divide both sides by 12.4:
$0.8516... = (1-r)^{20}$
Do twenty root on both sides:
$\sqrt[20] {0.8516...} = \sqrt[20] {(1-r)^{20}}$
$0.992... = 1-r$
Add r to both sides:
$0.992... + r= 1$
Take 0.992... away from both sides:
$r \approx 0.007999$